Concrete pile



Jun- 13, 1944. H. (5. cs. G. RICHES CONCRETE PILE Filed Nov. 1'7, 1939 3Sheets-Sheet 2 Inventor H.G.Cw.G.'R\CHE5 by 5km mfiu hi Attorney June13, 1944. RlCHEs I 2,351,288

CONCRETE PILE Filed NOV. 17, 1959 3 Sheets-Sheetfi Fig. 7.

Inventor H.G'.6.G.'R\C HES Attorney Patented June 13, 1944 CONCRETE PILEHarry Gordon George Greatorex Riches, Singapore, Straits Settlements,assignor to Shaw Darby & Company Limited Application November 17, 1939,Serial No. 305,034 In. Great Britain November 22, 1938 3 Claims.

This invention relates to concrete piles.

There are tWo methods of sinking concrete piles in common use atpresent, namely driving precast piles by impact and casting the piles insitu. Each possesses disadvantages. Another known method, not in commonuse, comprises using a tube which is driven into the ground, so as toform a socket for a precast pile which is lowered into the tube, thetube being subsequently removed. The end of the tube may be closed by aloose shoe during the driving. An important object of the invention isto provide such improvements in this last method as to render itsuperior to either of the methods in common use.

Another object of this invention is to provide improved pile unitscapable of being formed into an extremely strong pile.

Another object of the invention is to improve the reinforcement at thjoints of a built-up concrete pile.

Other objects of the invention will appear as the description proceeds,reference being made to the accompanying drawings, in which Figure 1 isa vertical section through the lower part of one pile in the course ofthe sinking process.

Figures 2, 3 and 4 are cross-sections on the lines II-II, IIIIII andIV--IV respectively of Figure 1;

Figure 5 is a perspective view of a set of pile units of the kind usedin the pile shown in Figure 1;

Figures 6 and 7 are similar perspective views of modified sets of pileunits.

Referring first to Figures 1 to 5, the first step in sinking the pile isto sink in the ground a tube l5, the bottom of which is closed by aloose shoe 5. The pile is then assembled above ground from a pluralityof precast units and lowered into the tube. Each unit is shaped to forma joint member, spigot-and-socket joints being preferred and each of theunits, except the bottom one, having a spigot of standard size at oneend and a socket of standard size at the other. Preferably, the pile ismainly composed of a single long unit of standard size, which iestimated to be rather shorter than the final length of any pile inagroup which is to be sunk, and the bottom of such a long unit is shownat I. cast units, which are much shorter than the long unit and arepreferably made in a number of standard sizes, are then joined to thelong unit until a pile of the required size is formed. It is, however,possible to form a satisfactory com- Short preposite pile entirely ofshort precast units, and in some cases this may be desirable.

The whole pile is formed in situ above ground, i. e. before it islowered into the tube. This is easy, because once the tube has beendriven the depth of the base of the pile is known, so that the requiredlength of the final pile can be calculated exactly. In almost any groundthis length will vary slightly from pile to pile and cannot be predictedwith any degree of accuracy in ad- Vance, so that the invention enableswaste to be avoided in having to cut ofi lengths from a precast pile,and also prevents the possibility of having to add to the pile after itis in position. Thus the final pile can be guaranteed to be in the samecondition as it was when constructed under supervision above ground.Moreover, as it is placed in position, and not driven, it i not affectedby driving conditions.

In most cases it is preferable to add the short units to the lower endof the long unit, since the lower part of the pile is usually onlysubjected to a pure compression. Figure 1 shows two intermediate precastshort pile units 2a and 2b and a bottom precast pile unit 3, the latterhaving a foot 4 which rests in the shoe 5, and which forms a base forthe whole pile. Each of the units 2a and 21) has a cylindrical socket Bextending for the greater part of its length and a tapered spigot 1,which has a shoulder 8 which fits inside the rim of the adjacent socketand so aligns the two units correctly. Each unit is provided with fouraxial reinforcing members, those of the unit 2a being numbered 9a andthose of the unit 212 being numbered 9b These reinforcing members passthrough the base of the unit and project upwards into the socket anddownwards past the spigot I, so that they run almost to the bottom ofthe adjacent socket. Thus, when a pair of units is assembled, the socketof the joint has eight axial reinforcing members running through it,four belonging to the unit above and four belonging to the unit below.When the joint is assembled, the socket i filled with cement grout orthe like M, so that when this sets a very powerful reinforced joint isformed.

In addition each joint is provided with a pair of transverse lockingbars in, il, which pass through registering holes I 6, I! in the spigotand socket respectively and provide a positive connection between theadjacent units. Their presence prevents the possibility of the jointbeing disturbed during the removal of the tube and while the cement inthe socket is setting and in addition adds greatly to the reinforcementof the pile. Each unit is also reinforced by two members I2 and I3 whichrun substantially axially along the wall of the socket. At its lowerend, each member I2 or I3 is bent inwards so that it runs into thespigot and is then bent right back and up so that it passes up theopposite side of the socket. When the bar I] is inserted through thespigot of the unit the lower part of the member I2 is thus looped roundit. Each free upper end of each member I2 and I3 is turned back onitself so that it encircles one of the locking bars when this isinserted through the socket of the unit; this is clearly shown in Figure1 at the upper part of the unit 2b, where the member I3 is crankedaround the locking bar II. The interlocking of the reinforcement of theunits with the locking bars is a very important feature of theconstruction, as it provides continuous reinforcement in the compositepile, which greatly adds to its strength. The members I2 and I3 arebound in by circumferential reinforcing mem bers I8, which support thesocket against any tendency to split under the action of the spigot whenthe pile is submitted to bending stresses.

The lowermost unit 3 has a socket of similar construction to those ofthe units 2a and 2b, but instead of a spigot itis provided with the foot4 which is shaped to fit into the shoe 5. The units 2' and 3 are roundin cross-section, whereas the main length of the pile I is octagonal.The long unit I is provided with a spigot I9'of construction similar tothose of the units 2a and 2b, and with continuous axial reinforcement 28bound by reinforcement 2I.

Figure 6 shows a set of units of modified construction, in which onlyone transverse locking bar In is provided for each joint.

Figure 7 shows another set of units, 22, arranged to make screw jointswith one another. Each unit 22 has a spigot 23 and a socket 24. Thespigot 23 is encased in a thin steel cup 25 formed with a screw-thread26, and the socket 24 is lined by another thin steel cup 21 formed'witha meshing screw-thread 28. The cups may be used as mould parts in whichthe spigot and socket are formed during the casting of the unit. Theyare formed with holes I6 and I! for the reception of locking bars. Theunits 22 are reinforced in the same way as the units Za'and 211.

It will be observed that each of the units shown in Figures 5, 6 and7has an end so shaped to engage another that the units either interlockagainst axial displacement or can be so locked by locking means engagingboth units. Such locked units may be used for underpinning or forming animpact-driven pile where there is lim ited headroom for driving.Further, other forms of joints may be used between the units, forexample, the ends of a unit may be formed as the component members of abayonet or equivalent joint.

In sinking the pile, the tube I5, closed by the shoe is driven in untilfirm ground is found. The depth of the shoe can then be calculated fromthe length of the tube inserted. If, for example, the tube had beendriven in fifty feet and precast units forty feet long were availabletogether with short units of three feet long, the final pile would bebuilt up as shown in Figure 1 from one long unit I, two intermediateunits 2a and 2b and a bottom unit 3. Each joint is assembled by fillingthe socket of the lower unit with cement or the like, lowering the nextunit into the socket so that the reinforcing bars 911 of the upper unitlie between the bars 9b of the lower unit and so that the transverseholes through the spigot and socket register, and finally driving thelocking bars II) and II through these holes.

When the complete pile has been built up it is hoisted and lowered intothe tube until the bottom unit rests upon the cast iron shoe. Cementgrout or fine concrete is then poured down the tube and around the pile,after which the tube is extracted.

It is within the invention to drive pipe sections into the groundoutside the tube, so that in the final pile the precast units do notconstitute the whole pile, but rather a solid core within the pipesections.

I claim:

1. A pair of similarly shaped concrete pile units each having an endshaped to engage and interlock with an end of the other in a spigot andsocket manner, each unit having imbedded longitudinal reinforcingmembers some of which extend beyond the spigot end of the respectiveunits, the spigot receiving socket portion of each unit being axiallyextended to receive the protruding end portions of the reinforcingmembers, and transverse locking means passing through the shaped ends ofadjacent units and interlocking with imbedded portions of thereinforcing members of both units, said socket extension being filledwith concrete to imbed the protruding ends of said reinforcing members.

2. A concrete pile comprising at least two similarly shaped reinforcedconcrete units, each unit having a projecting end and a socketed end,the

projecting end of one unit interfitting with the socketed end of anadjacent unit to form the pile, each unit having imbedded longitudinallyextending reinforcing bars, some of said reinforcing bars extendingbeyond the projecting end of the re- --spective units, the socket ofeach unit being extended axially to receive the protruding end portionsof said reinforcing bars of an adjacent unit, and means coacting withthe said imbedded portions of said reinforcing bars in each unit to re-,

strain adjacent units against substantialrelative rotary andlongitudinal movement.

3. A concrete pile comprising at least two similarly shaped reinforcedconcrete units, each unit having a projecting end and a socketed end,the

1 projecting end of one unit interfitting with the socketed end of anadjacent unit to form the pile, each unit having imbedded longitudinallyextending reinforcing members, said members having loop formations atopposite ends disposed respectively in the projecting end portion and inthe wall portion of the socket at diametrically opposite points thereof,said loop formations of adjacent units being aligned when said unitsare.

assembled in interfitting relation, and transverse locking pinsextending through the socket wall and projecting end portion of adjacentunits and through said aligned loop formations whereby to,

lock adjacent units against substantial relative rotary and longitudinalmovements.

HARRY GORDON GEORGE GREATOREX RICHES.

